/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.xd.dirt.stream.zookeeper;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.Deque;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import org.apache.commons.collections.CollectionUtils;
import org.apache.curator.framework.CuratorFramework;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.util.Assert;
import org.springframework.xd.dirt.core.DeploymentUnitStatus;
import org.springframework.xd.dirt.core.StreamDeploymentsPath;
import org.springframework.xd.dirt.stream.Stream;
import org.springframework.xd.dirt.stream.StreamDefinition;
import org.springframework.xd.dirt.stream.StreamRepository;
import org.springframework.xd.dirt.util.PagingUtility;
import org.springframework.xd.dirt.zookeeper.Paths;
import org.springframework.xd.dirt.zookeeper.ZooKeeperConnection;
import org.springframework.xd.dirt.zookeeper.ZooKeeperUtils;
/**
* Stream instance repository. It should only return values for Streams that are deployed.
*
* @author Mark Fisher
*/
// todo: the StreamRepository abstraction can be removed once we are fully zk-enabled since we do not need to
// support multiple impls at that point
public class ZooKeeperStreamRepository implements StreamRepository, InitializingBean {
private static final Logger logger = LoggerFactory.getLogger(ZooKeeperStreamRepository.class);
private final ZooKeeperConnection zkConnection;
private final PagingUtility<Stream> pagingUtility = new PagingUtility<Stream>();
private final RepositoryConnectionListener connectionListener = new RepositoryConnectionListener();
@Autowired
public ZooKeeperStreamRepository(ZooKeeperConnection zkConnection) {
this.zkConnection = zkConnection;
}
@Override
public void afterPropertiesSet() throws Exception {
zkConnection.addListener(connectionListener);
if (zkConnection.isConnected()) {
// already connected, invoke the callback directly
connectionListener.onConnect(zkConnection.getClient());
}
}
@Override
public Iterable<Stream> findAll(Sort sort) {
// todo: implement sort support
return findAll();
}
@Override
public Page<Stream> findAll(Pageable pageable) {
return pagingUtility.getPagedData(pageable, findAll());
}
@Override
public <S extends Stream> S save(S entity) {
// stream instances are "saved" when a StreamDeploymentListener deploys a stream
return entity;
}
@Override
public <S extends Stream> Iterable<S> save(Iterable<S> entities) {
// stream instances are "saved" when a StreamDeploymentListener deploys a stream
return entities;
}
@Override
public Stream findOne(String id) {
CuratorFramework client = zkConnection.getClient();
String path = Paths.build(Paths.STREAMS, id);
try {
Stat definitionStat = client.checkExists().forPath(path);
if (definitionStat != null) {
byte[] data = client.getData().forPath(path);
Map<String, String> map = ZooKeeperUtils.bytesToMap(data);
Stream stream = new Stream(new StreamDefinition(id, map.get("definition")));
Stat deployStat = client.checkExists().forPath(Paths.build(Paths.STREAM_DEPLOYMENTS, id));
if (deployStat != null) {
stream.setStartedAt(new Date(deployStat.getCtime()));
stream.setStatus(getDeploymentStatus(id));
return stream;
}
}
}
catch (Exception e) {
throw ZooKeeperUtils.wrapThrowable(e);
}
return null;
}
@Override
public boolean exists(String id) {
return null != findOne(id);
}
@Override
public List<Stream> findAll() {
try {
return findAll(zkConnection.getClient().getChildren().forPath(Paths.STREAM_DEPLOYMENTS));
}
catch (Exception e) {
throw ZooKeeperUtils.wrapThrowable(e);
}
}
@Override
public List<Stream> findAll(Iterable<String> ids) {
List<Stream> results = new ArrayList<Stream>();
try {
for (String stream : ids) {
Stream s = findOne(stream);
if (s != null) {
results.add(s);
}
}
}
catch (Exception e) {
throw ZooKeeperUtils.wrapThrowable(e);
}
return results;
}
@Override
public long count() {
try {
Stat stat = zkConnection.getClient().checkExists().forPath(Paths.STREAM_DEPLOYMENTS);
return stat != null ? stat.getNumChildren() : 0;
}
catch (Exception e) {
throw ZooKeeperUtils.wrapThrowable(e);
}
}
@Override
public void delete(String id) {
logger.info("Undeploying stream {}", id);
String streamDeploymentPath = Paths.build(Paths.STREAM_DEPLOYMENTS, id);
String streamModuleDeploymentPath = Paths.build(streamDeploymentPath, Paths.MODULES);
CuratorFramework client = zkConnection.getClient();
Deque<String> paths = new ArrayDeque<String>();
try {
client.setData().forPath(
Paths.build(Paths.STREAM_DEPLOYMENTS, id, Paths.STATUS),
ZooKeeperUtils.mapToBytes(new DeploymentUnitStatus(
DeploymentUnitStatus.State.undeploying).toMap()));
}
catch (Exception e) {
logger.warn("Exception while transitioning stream {} state to {}", id,
DeploymentUnitStatus.State.undeploying, e);
}
// Place all module deployments into a tree keyed by the
// ZK transaction id. The ZK transaction id maintains
// total ordering of all changes. This allows the
// undeployment of modules in the reverse order in
// which they were deployed.
Map<Long, String> txMap = new TreeMap<Long, String>();
try {
List<String> deployments = client.getChildren().forPath(streamModuleDeploymentPath);
for (String deployment : deployments) {
String path = new StreamDeploymentsPath(Paths.build(streamModuleDeploymentPath, deployment)).build();
Stat stat = client.checkExists().forPath(path);
Assert.notNull(stat);
txMap.put(stat.getCzxid(), path);
}
}
catch (Exception e) {
//NoNodeException - nothing to delete
ZooKeeperUtils.wrapAndThrowIgnoring(e, KeeperException.NoNodeException.class);
}
for (String deployment : txMap.values()) {
paths.add(deployment);
}
for (Iterator<String> iterator = paths.descendingIterator(); iterator.hasNext();) {
try {
String path = iterator.next();
logger.trace("removing path {}", path);
client.delete().deletingChildrenIfNeeded().forPath(path);
}
catch (Exception e) {
ZooKeeperUtils.wrapAndThrowIgnoring(e, KeeperException.NoNodeException.class);
}
}
try {
client.delete().deletingChildrenIfNeeded().forPath(streamDeploymentPath);
}
catch (KeeperException.NotEmptyException e) {
List<String> children = new ArrayList<String>();
try {
children.addAll(client.getChildren().forPath(streamModuleDeploymentPath));
}
catch (Exception ex) {
children.add("Could not load list of children due to " + ex);
}
throw new IllegalStateException(String.format(
"The following children were not deleted from %s: %s", streamModuleDeploymentPath, children), e);
}
catch (Exception e) {
ZooKeeperUtils.wrapAndThrowIgnoring(e, KeeperException.NoNodeException.class);
}
}
@Override
public void delete(Stream entity) {
Assert.notNull(entity, "stream must not be null");
delete(entity.getDefinition().getName());
}
@Override
public void delete(Iterable<? extends Stream> entities) {
for (Stream stream : entities) {
delete(stream);
}
}
@Override
public void deleteAll() {
try {
List<String> children = zkConnection.getClient().getChildren().forPath(Paths.STREAM_DEPLOYMENTS);
for (String child : children) {
delete(child);
}
}
catch (Exception e) {
//NoNodeException - nothing to delete
ZooKeeperUtils.wrapAndThrowIgnoring(e, KeeperException.NoNodeException.class);
}
}
@Override
public Iterable<Stream> findAllInRange(String from, boolean fromInclusive, String to, boolean toInclusive) {
List<Stream> all = findAll();
if (CollectionUtils.isEmpty(all)) {
return Collections.emptyList();
}
Collections.sort(all);
List<Stream> results = new ArrayList<Stream>();
for (Stream stream : all) {
if (stream.getDefinition().getName().compareTo(to) > 1) {
break;
}
if (stream.getDefinition().getName().compareTo(from) < 0) {
continue;
}
results.add(stream);
}
return results;
}
@Override
public DeploymentUnitStatus getDeploymentStatus(String id) {
String path = Paths.build(Paths.STREAM_DEPLOYMENTS, id, Paths.STATUS);
byte[] statusBytes = null;
try {
statusBytes = zkConnection.getClient().getData().forPath(path);
}
catch (Exception e) {
// missing node means this stream has not been deployed
ZooKeeperUtils.wrapAndThrowIgnoring(e, KeeperException.NoNodeException.class);
}
return (statusBytes == null)
? new DeploymentUnitStatus(DeploymentUnitStatus.State.undeployed)
: new DeploymentUnitStatus(ZooKeeperUtils.bytesToMap(statusBytes));
}
}